Manufacture of stay-bolts for boilers.



J R. FLANNERY 6; E. I. 00008. MANUFACTURE OF STAY sons FOR BOILERS.

APPLlC-XTION FILED FEB. 2|. I917.

Patented Oct. 15, 1918.

i t 1 J mimw VENTORKSI WITNESSES I fr I j J -M Q @Jylw W Alfgrngj/UNITED STATES PATENT OFFICE.

JOHN ROGERS FLANNERY AND ETHAN I. DODDS, OF PITTSBURGH, PENNSYLVANIA,ASSIGNORS T0 FLANNERY BOLT COMPANY, OF PITTSBURGH, PENNSYLVANIA.

MANUFACTURE OF STAY-BOLTS FOR FOILERS.

Specification of Letters Patent.

Patented Oct. 15, 1918.

Application filed February 21, 1917. Serial No. 150,204.

To all whom it may concern:

Be it known that we, Jonx R. FLANNERY and ETHAN I. Doons, citizens ofthe United States, and residents of Pittsburgh, in the county ofAllegheny and State of Pennsylvania, have invented certain new anduseful Improvements in the Manufacture of Stay- Bolts for Boilers; andwe do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart, to which it'appertains to make and use the same.

This invention relates to improvements in the manufacture of stayboltsfor boilers and more particularly to such as are of the type known inthe art as flexible staybolts and formed with tell-tale holes,the objectof the present invention being to provide a simple and efficient methodof making a stay bolt from a bar having a bore extending continuouslythrough the same from end to end,

i and forming an integral head thereon in such manner as to avoidcontracting or elosing the bore during the formation of the 'head.

With this object in view, the invention consists in certain novelfeatures in the method of making a staybolt as hereinafter set forth andpointed out in the claims.

In the accompanying drawings, Figure 1 is a view of atubular bar fromwhich the bolt may be made; Fig. 2 is a cross section of the same; Fig.3 is a view illustrating the first step in the method of-forming thehead; Fig. 4. is a view illustrating the beginning of the second step,Fig. 5 is a view illustrating the conclusion of the second step, andFig. 6 is a view showing the manner in which the tell-tale bore may bepermanently closed atthe headed endof the bolt.

1 represents a tubular bar or blank from which the staybolt is made,thebore forming the tell-tale hole for the finished bolt. The bar, or blankmay comprise two grooved members 3, 4, welded together as indicated inFig. 2. One end of the baror blank may be heatedand a conical mandrel ormale die 5 may then be forced into the bore 2 at one end thereof topartially expand the metal at the end of the bore, as indicated in Fig.3. v I

The end portion of the bar will then be subjected to the action of twofemale dies 67 with a conical male die or mandrel 8 extending from thefemale die 7- and entermg the partially expanded bore,the free endportion 9 of the die or mandrel 8 being made cylindrical to conform tothe normal contour of the bore 2. i The female dies 6, 7 are thenbrought together as indicated in Fig. 5, resulting in upsetting orexpanding the metal of the end of the bar into the cavities of the dies6-7 and aroundthe die or mandrel 8, and thus forging a head 10 on theouter end of the bolt,said head being, in the present instance,spherical in form, although it may be given any other contour desired.

WVhen the bolt shall have been removed from the dies, we prefer to closethe end of the bore at the headed end only of the bolt, in any suitablemanner (as by means of a plug 11), so that the tell-tale hole formed bysaid bore shall extend from the inner end of the bolt to a point withinthe head at the outer end thereof.

Having fully described our invention what we claim as new and desire tosecure by Letone end of the tubular bar, forging the ex panded endportion of the bar into a head, and then permanently closing the bore atthe headed end of the bolt.

2. The herein described method of making a staybolt having a tell-talebore, consisting in heating one end portion of a tubular bar, forcing aconical mandrel into the bore at the heated end of the bar and expandingthe latter, disposing thesaid portion of the bar between femaledies,forging a head on the end of the bar between said dies andsimultaneously inserting a mandrel into said bore beyond the portion ofthe bar on which the head is forged,and finally closing the telltalehole at the headed end of the bolt.

In testimony whereof, we have signed this specification in the presenceof two subscribmg witnesses.

JOHN ROGERS FLANNERY. ETHAN I. DODDS. Witnesses F. H. ALLISON. EDWIN S.Ryan.

